This project aims to identify inhibitors of an upstream enzyme - aminoadipate semialdehyde synthase (AASS) - to reduce accumulation of AASA/P6C and serve as substrate reduction therapy for PDE. During this period, the collaborative team continued its development of a robust screening-amenable assay to enable quantitative high-throughput screening of AASS. Following completion of pilot screening, the team will pursue large-scale screening of NCGC's small molecule libraries, and will proceed with hit identification, validation and characterization.